Propeller.



G. GAYS.

PROPELLER.

APPLmATIoN FILED 11011.13, 1912.

Patented Dec. 9, 1913.

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Specication of Letters Patent.

?atentedDec.9, laila Application led November 13, 1912. Serial No. 731,118.

To all 'whom t may concern:

Be it known that I, Ginsnrrn GAYS, a subject of the King of Italy, who have de clared my intention .of becoming a citizen of the United States, residing at Los Angeles, county of Los Angeles, and State of California, have invented new and useful Improvements in Propellers, of which the following is a specification.

This invention relates to improvements in propellers for aquatic use, more particularly to thatv class and description as shown and described in my rior United States Letters Patent, Num r 958,108, issued to me May 17, 1910.

In the further adaptation and utilization of propellers for vessel-propulsion, which embody means for producing relatively increased degrees of operative thrust upon the resisting mass of water, wherein the water is set in motion by the revolutions of the propeller to the end that the water is utilized as a` bearing agency for the propeller through a constantly increasing range of propulsive activit f, from the point at which the forward portion of the propeller first engages a given mass of water to the point at which such mass of water is finally thrown o1' discharged from the propeller and which embody the means for providing apropeller having a series of members or blades` of varied thrust areas, each of which members or blades have their edges overlapping with relation to each other. It -is found with respect to the practice, that the elimination of propulsive vibration, that is, reducing said vibration to a minimum is rather difficult. In order to reduce the vibra-tion resultant of the propulsive revolution it is found that each of the members or blades of the propeller must necessarily be of equal increasing operative dimensions of thrust producing areas and that a giveu mass of water must be in equal resistance to each of said members or blades in the thrust producing propulsion thereof, as the propeller is rotated 1n said given mass of water.

In this invention I propose to employ members or blades on the propelling shaft, each of which are so constructed as to conform t0 the lines 0f a spiral screw of constantly increasing thrust area with respect to the forward propulsion thereof; each of said spiral members or blades having their starting points on the shaft, one slightly leading the other and each havin its concave water resistance surface slig tly shallower than that of the member or blade following, so that an equal mass of water is moved over the resisting surfaces of each member or blade in exactly the same duration of time, thatis, from the time a given mass of water is engaged by one of said members or blades to the time said mass is finally discharged therefrom, is equal with respect to the engagement of a like amount of water in, or b one of the other members or blades. The acks or rearward faces of the members or blades are of convex formation, of such irregular curvature that the dead water .not engaged by the revolution of the propeller is in minimum resistance thereto and the action of the Water iu motion in the spiral between any two of such members or blades on the back of the leading member or blade is in minimum resistance to said water in motion, so that the propulsive activity of the propeller is not retarded to any great degree by the displacement of' the Water in motion in the spirals, nor by the dead water in front of the propeller, which is the back of the members or blades.

An object of the invent-ion is the provi# sion of a propeller of the above general character which is comparatively simple and inexpensive in construction, embodying positiveness in operation and that is superior in point ot' relative eiiiciency and serviceability.

Another object of the invention is pri- .marily the provision of an lmproved pro- 1 peller of the character stated, in which the Q vibration 1s substantially null, and in which i the resultant minimum Vibration of the revoluble composite parts is uniform with relation to the centrifugal force or propulsive activity and the equal thrust areas of each of the composite parts.

A further object of the invention is the provision of an improved propeller of the stated character in which each of the mem- -bers or blades thereof is provided with a so arranged on said surfaces as to retard the accelerated momentum of the Water being `deliected over said surfaces, which is the 'means of lengthenmg the duration of tlme in which a given mass of water would otherwise have been discharged from the ends of said members or blades, thereby greatly increasing the propulsive thrust of the propeller, which results in a considerable saving of fuel consumption.

A still further object of the invention is to provide members or blades of spiral formation of the character'described, which take olf from the propelling shaft at different stations longitudinally thereof, so that one leads the other and each overlaps one and underlaps another of said blades; each of said stations being equally' spaced from the other circumferentiallv of said shaft.

ln practice it is found that my improved propeller picks up the dead Water and sets it in motion on the waterV resistin thrust producing surfaces so that the d1- rection of movement of said water is toward the axial center of the propeller thereby increasing its eliciency of thrust productiveness. l y

lVith the above general objects in view the invention further consists in the novel provision, forma-tion, construction, organ ization, combination and relative arrangement of parts, members and features, allias hereinafter described, shown in the drawings and finally pointed out in the claims.

In the drawings: Figure l is a side elevation exteriorly showing a propeller con.- structed in accordance with the invention, the dotted lines denoting a portion of a vessel, to which the invention is connected; Fig. .2 is an end view of the parts shown in Fig. 1, looking in the direction of the appended arrow; Fig. 3 is a view of one of the members or blades as it would appear if removed from the shaft; and Figs. l and 5 are each detail views taken on the lines X4`X* and XS-Xs respectively of Figs. Q and 3, showing the approximate crosssectional formation of the members or blades shown in the several views. l

Like characters of reference designate like parts throughout the several `views of the drawings.

Referring with particularity to the drawings, the members or blades of the propeller embodying the invention are designated by the characters A, B and C respectively, in the present instance there being three of such members or blades, each bein of spiral screw formation and extending ongitudinelly of the shaft D which latter represents the customary power shaft extending from the motor or other propulsive means for r0- tating the shaft and thereby said members or blades.

a. Z) and. e represent the points on the ,shaft D where the spiral members or blades A, B and C start on the circumference thereof, the member or blade' A being rst and starting as at a. and extending rearwardly of said shaft, the member or blade B starting as at b which is spaced a predetermined distance to the rear of the point a and 120 degrees therefrom on the circumference of said shaft, and the miem'ber or blade C starting as at c, whichl is to the rear of the point b and 120 degrees therefrom on the circumference of said shaft; the member or blade A overlapping the member or blade B and underlapping the member or blade C, the member or blade B overlapping the member or blade C and underlapping the member or blade A, and the member or blade C overlapping the member or blade A and underlapping the member or blade B. This arrangement spaces the points a, b and c one-third of the shaft circumference or 120 degrees apart on the periphery of said shaft and one slightly leading the other longitudinally of said shaft. The rearward ends d, e and fof the menrbers or blades A, B and C, are in true veiticalfalinement with each other, so it will ybe seen that'the member or blade A is the longer spiral, the member or blade B being the next longest and the member or blade C being the shorter of the three and owing to this difference of length, it is necessary that the concave curvature or water resisting surface g of the member or blade 'A be of shallower dept-h than the depth of the surface L of the member or blade B and as the member or blade C is the shorter, it mustnecessarily be of the greatest depth of the like concave surface e'. The outer edges j, 7c and Z of said members or blades A, B and C conform to a helix from the points a, b and o as they recede radially from said shaft as shown in Figs. 1 and 2 of the drawings; the depth of the spiral screw from the helical edge to the shaft at any given point being equal with relation to each of the other spiral members or blades. The backs or rearward faces m, n and o, of the members or blades A, B and C are of convex curvature approximately the opposite of the concave surfaces g, h and z' so as to bein minimum resistance tothe dead Water as it ispiclred V up by the propeller and as it is set in motion and accelerated over the concave vWater resisting surfaces g, L and 11 in the spiral between any two of said members or blades. The circular ribs E, F and G are provided on the surfaces g, 71, and z', extending common to an equal radius of the center of the shaft, and of constantly increasing dimensions of projection outwardly from said surfaces, forthe purpose 'of retarding the accelerated water being defiected over said surfaces in the spiral intermediate the overlapping members or blades, which is the spaces between said members or blades, thereby greatly increasing the forward thrust or propulsive activity by lengthening the duration of time in which a given mass of water would otherwise have been discharged from the ends d, e and f of said members or blades.

It is manifest from the foregoing that the inertia of the water engaged by the members or blades of the propeller is utilized for greater thrust'roductiveness. The overlapping and underlapping features of the members or blades impart an even motion, with an absolute lminimum vibration in the operation of the propeller.v

The invention may be utilized with two members or blades instead of three, as herein shown, wherein each member or blade overlaps and underlaps the other of such members or blades.

In practice it is found that the three member or blade type is especially adaptable for oceanic service in the vicinity of the coast line or off and about the reefs, shoals or small islands, where there is various vegetable growths in the water usu ally in the form of help, but in ,some instances win the form of so called marine gardens, consisting of many various and different kinds of such ve tion of blades is such t at when growths of the above character are' encountered the revolution thereof has a natural or inherent tendency to cast most of said growth without the radius of revolution, while a small per cent. ,is cut into smalll pieces, as it is taken' into the spiral with the dead water.

I do not desire to be understood as limting myself to the specific provision, formation, construction, organization, combination, and relative arran ement of parts, members and features as erein shown and described; but reserve the right to vary the same in adapting the improvements to varying conditions of use, without departing from the spirit of or sacrificing any of the advantages of the terms of the following claims.

Having thus fully described my invention, what I claim as new therein, and desire to secure by Letters Patent, is

l. A propeller comprising a lurality of blades in which the revoluble egective 'propelling surface conforms yto a spiral, each blade overlapping one and underlapping another of such blades; said spiral blades betation. The formaasiat ing of different lengths of spiral and of diercnt depths of concave curvature; the lengths of spirals and the depths of the concave surfaces being such that. each blade exerts equal propulsiva thrust from a given mass of water in an equal duration of time; a shaft on which the propeller is mounted; each of said blades having its edge of helical conformation and being of equal distance from the shaft at a given point as it recedes from said shaft; and a circular rib on each of said water resisting surfaces ifor retarding the How of water in the spaces between the blades, substantially as described.

2. An improved propeller having a plurality of blades, each of which overlaps one and underlaps another of such blades; and a circular rib of varying dimensions of ,projection on the thrust producing Water resisting surfaces of each of such blades, to retard the defiecting water in motion over said surfaces', said ribs being circumferential of the center of the shaft, substantially as described.

3. An improved propeller having three blades, each of which overlaps one and underlaps another of such blades; a propelling shaft on which the blades are fastened; and a'circular rib of varying dimensions of projection on the thrust producing, water resisting surfaces of each of such blades, to retard the flow of the water over said surfaces; said ribs extending circumferential of the axial center of said propeller, substantially as described.

V4. An improved propeller having three blades, each of which overlaps one and underlaps another of such blades; a propelling shaft carrying the blades; and a circular 'rib of varying dimensions of projection on the thrust producing water resisting surfaces of such blades, to retard the flow of a given mass of Water over said surfaces; said blades being of spiral conformation longitudinally of the shaft, and each conforming to a helix of equal depth of the spiral screw, as at a given point it recedes from said shaft; said blades each being of concave curvature of slightly varying degrees, so that a given mass of water is productive of equalA thrust in each blade in an equal duration .of time, substantially as described.

5. An improved propeller having three blades eachof which overlaps one and underlaps another of such blades; a propelling shaft carrying the blades; and a circular rib of constantly increasing dimensions of projection on the thrust producing water resisting surfaces of each of such blades, to retard the flow of water over said surfaces; said blades being of spiral conformation of different lengths longitudiyand thereby produces equal propulsive efnally of the shaft and having their starting feet, substantially as described. points one leading the other and each con- In testimony whereof, I have hereunto forming to a helix at a given point of equal Signed my name to this specification in the 5 depth of the spiral scew in relationfto each presence of two subscribing Witnesses.

other as it recedes rom said sha t' said w 1 blades each being of concave curvature, of i I .GIUEPPE GAYS' Slightly different depth, so that a given Witnesses: mass of Water is productive of equal thrust W.' F. SEEMANN, 10 in each blade in an equal duration of time S. CoRDoNo. 

